Method of punching multicolor printing plates



sept. 27, 1938. 0, sEFFzlG 2,131,359

METHOD OF PUNCHING MULTICOLOR PRINTING PLATES Filed NOV. 2, 1937 mgl fir/) fw Patented Sept. 27, 1,938

UNITED STATES METHOD OF PUNCHING MULTICOLOR PRINTING PLATES Otto Seffzig, Berlin, Germany Application November 2, 1937, Serial No. 172,432

In Germany October 21, 1936 1 Claim.

For the multi-colored art printing, etched plates or galvanos are usually employed as printing plates, several galvanos of one original etching being necessary according to requirement, in 5 order to satisfy the demands of the book, art and multicolored printing.

The known machines, for instance also the socalled Iris press, cannot yet work satisfactorily, as they require curved printing plates, in which l0 the sensitive screen-picture is distorted so that an accurate registering cannot be attained.

In order that the printing plates when printing the one into the other give an accurate tting, tting crosses are drawn on the outer edges of the individual printing plates. These fitting crosses serve during the print and trial printing as directing means for the production of the socalled first prints for the control relating to iitters, and they have fulfilled their object as soon 0 as the iirst print has been declared fit for use. As in most instances, for the reason of editions or of precaution, galvanos are rst produced, the fitting crosses remain on the projecting rims of the zinc or'copper etchings, although they are no longer needed in the manufacturing proceeding of the galvanoplastic. As the tting crosses have no value whatsoever for the printer, they are removed prior to the insertion of the printing plates into the machine.

'I'he adjusting of the different colored partprinting plates in the printing press makes not too great diiiiculties when printing with flat part-printing plates, as displacing of the flat lying printing plates towards all directions, that is also in diagonal direction, is possible and therefore an accurate t can be attained without difficulty when printing the one into the other. As, however, the output of printing presses working with at printing plates is less than that of rotary printing presses, it has been proposed to use the rotary printing also for multicolored book printing.

It is then necessary, to employ for the platecylinder round printing plates which have to be produced by bending at printing plates or electrotypes, whereby, however, distortions of the screen-picture occur. The printer, who mounts the printing plate onto the plate cylinder, cannot, -as in the at printing, shift the printing forms towards all directions as shifting in diagonal direction is not possible. Further, the tting crosses are wiped out more and more during the gradual production of the deposits and, after the rear side has been coated with tin they are no longer v1sible at all, so that when inserting the deposits into the round-casting apparatus for back-casting of the deposits the caster is dependent ior the adjusting only on his feeling and on his eye. This is, however, as experience has shown not sufticient.

The invention relates to a method for rendering possible the fitting insertion of the individual deposits necessary for a multi-colored printing into a round-casting apparatus for the backcasting of the deposits, the chief characteristic feature of which consists in that the deposits having in known manner fitting crosses are perforated with small holes at the points of intersection of the fitting-cross lines, these holes serving as xed points during the production of larger holes in the deposits which with 'the wider holes are hung on accordingly thick pins in the casting apparatus. The deposits are threaded preferably on iitting pins of a perforating device with the holes provided on Vthe fitting crosses; in this perforating device the holes are made in the deposits by means of which holes these deposits are fixe-d for the back-casting on pins of the casting apparatus, so that separate adjusting is not necessary. The tting crosses are therefore used as important starting points during the back-casting of the deposits for the production of the round plates. Only after the perforating of the deposits, that is after the larger holes have been made which serve for hanging the deposits into the casting apparatus, the fitting crosses are no longer required.

The small holes in the points of intersection of the fitting crosses on the deposits are produced with a needle-like tool. The perforating device has two adjustable fitting pins, which are adjusted and secured in the adjusted position according to the fitting crosses of any color-deposit. The other copper-deposits threaded on the fitting pins are always in an accurately registering position. By the perforating rams ofthe perforating device carrying the iitting pins larger holes are madein all deposits which therefore are always in accurately registering position. If the copper deposits are hung into the casting apparatus on pins preferablyplaced near the casting mouth, all deposits in the casting apparatus are in a fitting position. v

The ievice for carrying out the method according to the invention is illustrated, by way of example, in the accompanying drawing in which Fig. 1 shows the deposits ready for insertion y into the casting machine.

or the like onto the pins d mounted in a plate f.

of a perforating device e. The diameter of these pins correspond accurately to the diameter of Y the small holes c, so that the deposits threaded on the pins d are all accurately secured in their position. This is necessary as the larger holes k which are made by the perforating rams h of the perforating device e in the deposits a` threaded on the pins d must have a quite determined, invariable position relative to the holes c in the point of intersection of the lines of the tting crosses b. The plate f of the perforating device is preferably of the size of the deposits a. The pins d arranged on plate j are preferably adjustable and for instance adapted to be secured in their adjusted position by means of a screw g. The perforating device may comprise two or more perforating rams h adapted to be moved singly or both at the same time by means of a hand lever i. By these perforating rams h the holes k are stamped into the deposits a, the stamping pin r determining the hole-diameter. On the casting apparatus m means are arranged near the casting mouth o which serve for suspending the deposits a into the casting apparatus. These means consist preferably of a bolt s mounted so that it can be shifted in axial direction and carrying at its front end a pin n. The diameter of this pin n corresponds accurately to that of the stamping pin r or of the holes Ic in the deposits a. 'I'he bolts s have annular grooves p serving as -notches for a locking bolt q and permitting to bring into or out of engagement the pins n with the holes k o! the deposits inserted into the casting apparatus m, the distance between the pins n corresponding to that between the holes lc.

By the method according to the invention a very accurate tter for the production of the multi-colored printing plates for rotary printing can be attained without dimculty and without the necessity of diiicult adjusting of the printing plate to be back-casted in the hot casting apparatus.

As, owing to the invention. the fitting crosses are no longer wanted for the insertion of the deposits into the casting apparatus, the corresponding rim of the deposits can be cut off, as soon as the holes Ic have been stamped into the deposits. A clean trimming of the deposits is then no longer necessary. The technical progress obtained by the invention consists therefore chiefly therein that it is now possible to produce the colored-part-printingfplates for rotary printing directly as perfect round plates in the desired radius, whereas it was hitherto necessary, to bend the Iplane part-color-printing plates whereby a defective picture production had to be taken into account as a great inconvenience owing to the distortion of the screens.

I claim:

A method for enabling the tting insertion oi.' the individual galvanic deposits of colored etchings necessary for a multi-colored printing into round casting apparatus for back casting of the deposits, and in which fitting crossed lines are formed on the deposits, said method consisting of perforating the iitting crossed lines on the deposits at the points of intersection of the crossed lines and using said perforations as stationary points and then producing larger holes in the deposits at other points for hanging up the deposits in the round casting apparatus.

O'I'IO SEFFZIG. 

